... now imagine if you had access to millions of similar data sets. You could easily draw maps, tracing communication and movement. You could see which individuals, families or groups were communicating with one another. You could identify any social group and determine its major actors.

That is precisely why the American Civil Liberties Union (ACLU) is suing the government for collecting the information in the first place, arguing that the phone metadata "gives the government a comprehensive record of our associations and public movements, revealing a wealth of detail about our familial, political, professional, religious, and intimate associations."

The ZEIT graphic clearly shows public movements and corresponding communications (i.e. who Spitz is talking to). Here's the politician traveling from Frankfurt to Cologne:

ZEIT ONLINEThe ACLU argues that this type of dragnet surveillance "is not authorized by Section 215 [of the Patriot Act] and violates the First and Fourth Amendments."

The ZEIT ONLINE graphic includes a calendar — each column corresponds to a day — that shows "when he was in a particular location and can be used to jump to a specific time period."

ZEIT ONLINELast month Rep. Mike Rogers (R- Mich.), who heads the House Intelligence Committee, argued that phone metadata from Americans is kept in a " lockbox" that can only be accessed if it becomes relevant to terrorism investigations.

But according to former NSA contractor Edward Snowden, that's not the case since NSA analysts can access the data at their discretion.

Nevertheless, privacy-minded senators such as Mark Udall (D-Colo.) don't understand why the NSA collects the data in bulk in the first place.

"I don't think collecting millions and millions of Americans' phone calls — now this is the metadata, this is the time, place, to whom you direct the calls — is making us any safer," Udall (D-Colo.) has said.

Udall has a point. It's hard to see the national security relevance of always knowing who and what Spitz communicates with as he travels/traveled through Berlin. ZEIT ONLINE